Air-compressing mechanism



Dec. 4, 1928.

G. E. HAZARD AIR COMPRESSING MECHANISM s-Sheet 1 I Filed June 11, 1924G. E. HAZARD AIR COMPRESSING MECHANISM 5 Sheds-Sheet 2 Filed June 11,1924 (25 a I I Dec. 4, 1928. 1,694,218

- G. E. HAZARD AIR COMPRESSING MECHANISM Filed June 11, 1924 5Sheets-Sheet 5 "2f L i Dec. 4, 1928. r 1,694,218

i G. E. HAZARD AIR COMPRESSING MECHANISM Filed June 11, 1924 5Sheets-Sheet 4 m .I E'i nu .iiiii'M-W W lmmm III! III Hllll Dec. 4,1928.

G. E. HAZARD AIR COMPRESSING MECHANISM Filed Ju'ne 11, 1924 5Sheets-Sheet 5 Patented Dec. 4,1928.

UNITED STATES team PATENT OFFICE.

Jemima EDGAR HAZARD, or RoonnsTnR, NEW ORK, ASSIGNOR T KELLOGG MANU-FACTUBING 00., or RoonEsrER,'1vEw YORK.

AIR-COMPRESSING MECHANISM.

Application filed June 11,

My invention relates to improvements in air compressing mechanisms. i IThe invention has for its object theprovisionof an improved aircompressing mechanism.. v

Another object of my invention is to provide a compressing mechanismparticularly adapted for use in garages, or gasoline filling stationsfor compressing air in a supply tank, or the compressor maybe used topump directly into pneuma tic tires as desired. The compressors are alsoused for spraying paint and in divers other industrial work.

A further object of my invention is to prowide an improved aircompressing mechanism v theair-being compressed in two stages andhavingimproved cooling means for cooling 'the air during the time it iscompressed.

, A still furtherobject of my invention is to provide an improved aircompressing mechanism whichis automatically stopped when the air in thereceiving tank has reached a pre-determined pressure, and automaticallystarted when the air pressure in the tank falls below a pre-determinedpressure. I Another and further ob 'ect of my invention is to provide animproved air compressing mechanism so constructed that it always startsagainst atmospheric pressure, thereby making the mechanism easy tostart, and the mechanism is further so constructed'as to collectdeposits of moisture and oil and'pre; vent them from being carried withthe air into the airstorage tank.

A still furtlier'object of my invention -is to provide an' improvedcheck valve for use in air compressing mechanisms.

Other further objects, novel features of construction, and improvedresults of my invention will appear in the following description andaccompanying drawings.

In the drawings:

Figure l'is a view in elevation of my improvedair compressing mechanism.

Fig. 2 is a'vert-ical sectional viewthrough the air compressor.

Fig. 3 is an end view of the COIIIPI'GSSOI, the compressor head beingbroken away and being shown in vertical section.- A

Fig. 4 is a transverse sectional view taken ona line 4--4.- of Fig. 2looking in the direction indicated by arrow. v Fig. 5 is a verticalsectional view through the switch.

Fig. 6 is a sectional view taken at .right angles to Fig. 5. i

Fig. 7 is a vertical sectional view of my improved check valve.

F 1g. 8 1s a vertlcal sectional vlew of a modified form of my'improvedcheck valve.

coiled pipe is an airconduitv and together with the fly-wheel andhousing act as a cooling medium for the compressed air in a manner whichwill be hereinafter more particularly described. The air is conveyedfrom the housing or retort B, past a safety valveD, through a checkvalve E,-and into a storage tank G.

The mechanism is automatic in operation, after havingbeen once started,-being driven through a suitable electric motor I, or the like, by a beltin engagement with the flywheel of the pump. The automatic feature ofthe mechanism is the switch H, operated through a diaphragm M, uponwhich is constantly acting the air pressure of the tank G through thepipe connection F. The switch H is of such a construction that it can beautomatically set to break the electric current connection to the motorI whenthe air pressure in the tanlgG has reached a predetermined pointand to automatically renew the electric connection to the motor whentheair pressure in the storage tank has fallen below a predeterminedpoint."

A pressure release valve K is in communication through the check valve Ewith the retort or air chamber B and is actuated by the switch H, sothat when the driving motor 'is automatically stopped, the release orescape valve K is actuated to allow the accumulated air pressure in theretort B to escape through the check valve and the release valve.

The purpose of this is that when the pressure in the storage tank fallsand the mechanism is started that the compressor or pump will startagainst zero, or atmospheric pressure and also to clean from the checkvalve any accumulated dirt, oil or moisture collected by the check valvescreen.

The compressor or pump is what is known as a two-stage compressor,consisting of a low pressure cylinder N and a high pressure cylinder O.

Having described my invention in general terms, a specific descriptionof the device will now be given, wherein similar reference numerals asused in the drawings designate similar parts throughout the description.

The compressor A is of a two-stage type, consisting of the low pressurecylinder N and the hi h pressure cylinder 0, mounted upon a suita 1ebase 10, through which extends the crank shaft'll, upon the front end ofwhich is suitably mounted a fiy-whecl 12. The cylinders N and O areprovided with pistons 13 and 14 respectively, and are provided withconnecting rods 15 having suit-able connection, as at 16, with the crankshaft 11. Thebase 10 has in its bottom an oil reservoir 17. A pump 18 isin communication with the oil reservoir and the lubricating system is ofa constant level splashing system type. The pump maintains the oil levelconstant in the tray 19 of the base and the connecting rods dip intosaid tray splashing oil into pockets above both the main bearings 20 andkeeping a constant flow in them, the excess returning to the reservoir.A steel baflle plate 21, between the cylinders and crank case preventexcess oil being thrown into the cylinders. This baflle plate isprovided with a small extending finger 100 bent downwardly whichcollects oil from the under side of the plate and conveys it to the oilhole 101 in the rear main bearing 20. A lubricating system of this typeassures proper lubrication to the working parts of the com ressor. Oilis supplied to the reservoir tirough the vent or spout L.

The head of the compressor is designated at 25 and is cast in one piece,as clearly ap-' ears in Fig. 4 of the drawing. Air is drawn 1nto the lowpressure cylinder N, through the inlet 26, past the valve 27 which hasbeen drawn downwardly from its seat, thus allowing the air to passaround it. Between the inlet 26 and the valve 27 there is mounted amuffler comprising the-concentrically arranged pipes 102 and 103. Thismufller construction causes the incoming air to follow a zigzag course.Without this device the air intake is very noisy but the mufiierovercomes this annoyance. This, of course, takes place on the downwardstroke of the low pressure piston and as that piston is driven upwardlythe valve 27 is forced against its seat thus closing the inlet 26. Asthe piston ascends, the air additionally lifts the valve 28 from itsseat and permits the air to enter the chamber 29 in the head 25. Thischamber has an outlet 30 from which leads the end 31 of the coiled pipe32.

The pipe 32 is formed in several coils, as

It will, therefore, be readily seen that the air 'is cooled afterleaving the low pressure cylinder of the pump and is deliveredto thehigh pressure cylinder at a low temperature, which is obviouslyadvantageous. The coiled pipe '32 is preferably made of copper.Attention is also directed to the factthat the cylinders created by thefan-blades of the fly-wheel.

of the pump are provided with fins.37, for

radiating the heat from them. It will also be seen that the housingaround the coiled pipe will also deflect the air against the cylinderand cylinder fins and thereby materially aid the cooling of thecylinder.

As stated, the air from the low pressure cylinder after having passedthrough the cooling coil 32, enters the high pressure cylinder throughthe channel 34, and past a suitable valve in the cylinder head into thecylinder. The valve at the bottom of this channel is constructed toopen, only on a downward stroke of the high pressure piston. As the highpressure piston ascends, the valve will close the inlet opening 34 andlift the valve 38 from its seat, thus allowin the air compressed in thehigh pressure cy inder to is mounted. The compressed air enters atoneside of this retort and passes out through the ipe 41 at the other side;The function of t is retort is two-fold, viz, first, it acts as any airfilter to collect any moisture or oil carried by the air and therebyassures that dry air is supplied to the storage tank; secondly, thechamber acts as a starting retort so that the compressor when firststarted will begin against zero, or atmospheric pressure. The manner inwhich the second function of the retort acts will be hereinafterdescribed. The air upon leaving the air chamber or retort B is dry andis carried to the storage tank G through the pipes 41 and 42. Mountedupon the pipe 41 is a safety valve/D. This safety valve is of the usualconstruction having a ball which is retained upon its seat through themedium of spring tension and is adjustable by a screw 43", so that thevalve a ping thecompressor fail to operate for any reason,'or'in theevent that the check valve B should fail to operate and thereby'allowexcessive pressure of air being built up in the com ressor itself. I

heck valve 'E'is' also mounted upon,

'the pipe 41, and is of aparticular construe-- tion. A specificdescription of the check valve will be hereinafter made.

An air pressure gauge 43 for designating the air pressure in the storagetank is usually provided, andin the formherein shown the gauge ismounted in the top of the check valve E.

A shut ofi valve 44 is provided in the pipe line 42, between the storagetank and the check valve. This valve provides a means whereby thecompressor can be made to pump air. directly through the outlet hose 45,if desired. It is sometimes desirable to pump directly'through theoutlet hose 45 as, for instance, when 'it may be desired to inflatelarge tires. Often a large truck comes in for air and if the storagetank is of a small air-capacity and should the air in'the tank be at alow point, without the'valve 44, it

would be necessary to fill both the storage tank and the tire at thesame time. Such a. proceeding would consume considerable time, whichcould be avoided by merely closing the valve 44 andpumping dlrectly intothe tire. In case any adjustment is necessary to the check valve, or inthe case the check valve should need cleaning, the valve 44 can beclosed and the air 'ressure in the storage tank retained, while tcleaning or adjustment of the check-valve takes lace.

The compressor pump is preferably driven through the medium of anelectric motor I having communication with the fly-wheel 12 of thecompressor by means of a belt 46. An

automatic self-adjusting idler pulley 'J is provided to keep the propertension onthe belt at all times. 1

Aremovable plug 47 is provided in the retort or air chamber B, so thatthe accumulated moisture or oil collected in this chamber can bedrawnoil. This will be necessary occasionally to prevent the same beingpassed on into the reservoir. Y

The switch for automatically stopping and starting the mechanism isdesignated at H. The switch is provided with a diaphragm M, upon whichis constantl acting the air-pressure of the reservoir The air pressureof the reservoir G is carried to the diaphragm through the pipeconnection F,.which is in communication with i the pipe 44, between thestorage tank and the check valve. The

" ing 52 upon one, end of which is supported a automatic switch Hconsists of a main housremovable cover 48 which extends above the top ofthe housing while the opposite end of the housing isprovided with anupwardly extending portion 55.

Pivotally mounted within the switch hous- I ing at 105 is a lever 106having. itsend 1 07 adjacent its pivotal support in contact with theswitch diaphragm M. The end 107 ofthe lever is in constant contact withthe diaphragm through spring tension caused by the coil spring108supported within the portion 55 of the switch housing by means of thebolt 109 and having its lower end connected to the end 110. It will bereadily seen that through the medium of the bolt nut 111 the tensionupon the spring can be adjusted as,

rent flows to the motor I through the ewitch.

bars 114.

Pivotally mounted above the lever 106 upon the downwardly extendingportion 115 of the i switch housing top is a lever 116 having a notchedend 117 The notched end of this lever engages the lower end 118 of therod 119 the upper end of which is fastened at 120 to the switch bars114. The lever 116 is provided with a downwardly extending arm 121having adjacent its lower end a notch 122 adapted to receive and engagethe free end 123 of a pivotally mounted arm 124 carried within theopening 125 in the lever 106. The notch 122 of the arm 121 is held inconstant engagement with the end 123- of the member 124 by reason ofthecoil spring 126 while a downward pull is put upon the" end 123 ofthearm124 by reason of the coil spring 127.

As clearly appears in the drawings, particularly Figures 1, 5 and 6, therelease valve K is mounted upon the switch housing between'the removablecover 48 and the upwardly' extending end portion 55. This re-' leasevalve is normally closed and has its inlet end' 128 in communicationwith the check valve E by means of the pipe 129. The outlet or escape ofthe'release valve is shown at 130 and can be provided with an extendingescape pipe 131 if desired. The release valve with the pipe 44 betweenthe storage tank and the check valveE. When-the ressure in the pressuretank which is constant y acting upon the switch dia hragin, issufficient to depress the end 110 0 the switehlever 106 against thetension of the coil spring 108 the pivotally mounted lever 116 will belifted upwardly through the medium of the downwardly extending arln 121and the pivotally mounted bar or lever 12% When this takes place theflow of current to the electric motor is broken as the end 117 of thelever 116 lifts the switch bars 114 from their contacts and breaks theelectric circuit. At the same time the lower end 132 of the needle valveof the release valve K is lifted through the action of the arm 133carried by the lever 116. When this needle valve rod is lifted therelease valve is opened and allows the air pressure in the reservoir Bto escape through the pipe 41, the check valve E, down the pipe 129' andthrough the outlet or esca e 130 of the release valve.

It will nowlie seen that there is no air pressure in the retort B or inthe pipe line between this retort and the check valve E or the releasevalve K so that when the compressor again starts it will start againstzero or atmospheric pressure. 7

Attention is directed to another important feature which is that whenthe pressure release valve is opened the air pressure in the chamber Breaches the release or escape valve K throu h the check valve E, whichwill dis-. charge t rough the check valve any foreign matter such as oilor water or carbon deposit which hasbeen collected by the screen 81 ofthe check valve. This dirt or foreign substance escapes through therelease valve K. It will therefore be seen that from the time the comressor is automatically stop ed the check va ve is likewiseautomatically 0 eaned.

It will be readily understood that when the pressurein the storage tankfills sufliciently to permit the spring 108 to lift the end 110 of thelever 106 that the switch bars will be lowered and make electricalcontact to startthe electric motor and that the release valve" K willlikewise automatically be closed.

It will, of course, be readily understood that the air, supplied to theoutlet hose 45 is controlledbya suitable valve 59.

In the form of the invention, as shown in the drawings, the entire unitis supported upon a suitable base 60, which is in turn mounted upon thereservoir G, in any suitable manner, such as by the circular bands 61.If desired, the reservoir can be mounted upon a hand truck or the like,so that the unit can be readily moved about as desired.-

As will readily appear from'the drawings,-

" the low pressure cylinder N is much larger in capacity than the highpressure cylinder 0. The air which is compressed on one stroke of thelower pressure piston is exhausted into the coil pipe 32. In compressingthe air from the low pressure cylinder into the high pressure cylinderthe difference in volume of the two cylinders causes a constant pressurein the low pressure cylinder regardless ofthe pressure which the highpressure cylinder is operating against. In the particular pump set forthin the drawings and de' scription the difference in volumes of these twocylinders give a constant pressure of 45 pounds per square inch which isa low pressure and which is never exceeded in the low pressure cylinder.In compressing the air in the low pressure cylinder heat. is of coursegenerated which causes the air to become expanded and if this air werenot cooled before reaching the high pressure cylinder the pressure oftheair in the high pressure cylinder, before compression in thatcylinder takes place, wouldbe greater due to the increase in volumethrough the heat expansion;- Furthermore, if the high pressure cylinderhad high temperature or hot air in it at the time it begins itscompression stroke the discharged air from that cylinder would be veryhot and would be expanded still further than would be the case if theair was at atmospheric temperature when it enters the high pressurecylinder prior to being compressed therein. By keeping down thetemperature of the air it is possible to take a larger volume of airinto the low pressure cylinder and the compressor is kept cooler whichincreases the efliciency considerably in respect to the amount of actualdischarged air under high pressure. It will therefore be seen that bdelivering air thus to the high pressure cy inder at a low temperaturemakes the mechanism a most efiicient two stage compressor.

Referring now to Figs. '7 and 8 of the drawing, I will describe modifiedforms of my check valve which may be put to many uses and therefore theescape ip'e 129' of Fig. 1 is not shown. The chec valve has beenformerly designated by. the letter E, and consists of a cast housing65.- At one side of the housing is a downwardly leading port or inlet66, which terminates at the bottom of the housing in an enlarged chamber'67. At the opposite side of the housing is an upwardly leading port oroutlet 68, which terminates at the top of the housing in a chamber 69.In the form herein shown, the chamber 69 is closed by a suitable plug 70in the top of which is carried the pressure gage 43. The bottom of thechamber 69 is provided with an outlet port 71. A plunger 72 is mountedwithin the chamber 69. he upper end of the plunger 72 is slightly re-.duced in size by flattening it as at 73, while the lower end of theplunger has an enlarged head 74. The head 74'of the plunger normallycloses the outlet port 71 of the chamber 69, as appears in-Fig. 7 of thedrawing. The purpose of the plunger being made in the manner shown anddescribed is only Cal found necessary to bring about the best operationand which will allow the air to pass easily around the body of theplunger and escape through the opening 68 of the check valve. Thisconstruction also permits the air to readily circulate over the top ofthe plunger in the chamber 69 of the check valve. The construction alsoprevents the plunger from sticking or jamming to the side Walls of thechamber 69 as the majority of the plunger surfaces have been eliminated.The upper part of the plunger in reality merely serves to form a guideso that the plunger will rest squarely on its seat instead of tipping toone side or the other which would probably happen were the plunger notproperly guided at its top. It has been further found that as airpressure acts over the entire area of the plunger the flattened sides atthe top are necessary as without them the plunger when rising from itsseat would compress air to a certain extent between its top and the topof the chamber 69 which would cause an improper reading of the pres- Thb ottom of the housing 65 is provided with a plug 75, which has aninwardly extending elongated hollow stem 76, the upper end of whichprojects into a socket which surrounds the lower end-of the outlet port71, so that the outlet port 71 of the chamber 69 registers with thechannel 77 of the stem. The stem is provided intermediate its lengthwith a series of ports 78 While the plug is provided with aseries ofradially disposed ports 79, which communicate with the plug chamber 80.A screen 81 is carried upon shoulders 82 and 83 of the stem, so that thescreen is in spaced relation to the stem 76,

and its outlet ports 7 8. A plug 84 is screwthreadedly mounted in thebottom of the plug chamber 80. This plug screw-threadedly carries ahollow stem 85, having an open bottom 86 and a. closed top 87. Adjacentthe top 87 of the stem, a port 88 is in communication with the interiorof the stem. The stem is provided at its outer end with a suitablehandle 89.

In using my'improved check valve in my compressor mechanism, the valveis mounted in the pipe-line between the compressor pump and the storagetank. The port 66 is in communication with the pump and constitutes theinlet port, while the port 69 is in communication with the storage tankand constitutes the outlet port of the valve. The drain cock in thevalve bottom is eliminated, the pipe 129 oining the check valve with therelief valve, being substituted. Itwill be seen that as the compressedair from the pump enters the port 66, the air will pass through thescreen 81, which will remove any foreign element from the air, and intothe stem channel 77, through the ports 78. The

stem 85. It will be readily seen that I have provided air will passupwardly through the hollow stem 76 and into the chamber 69, through itsbottom port 71, lifting the plunger 72 from its seat. Theair will thenpass from the chamber 79 through the outlet port 68 into the compressortank. The back pressure from the storage tank is constantly in thechamber 69 and acting upon the plunger 7 2 normally holds the plungerupon its seat thus sealing the chamber 69 to the air inlet. As thepressure gauge 43 is in communication with the oham er 69, the airpressure of the reservoir will be indicated upon the dial of the gauge.As the compressor supplies compressed air to the check valve, this airwill lift the This foreign substance will most probablyv be moisture,either Water or oil.

In the modified form the oil or water accumulated in the chamber 80 canbe drawn off by turning the stem 85 inwardly until the stem port 88 isabove the inner end of the plug 84. At this time the port 88 of the stemWill'be in communication with the plug chamber 80 and allow the oil andwater to drain from the chamber through the hollow a check Valve whichis easily cleaned, the stem 76 being integral with the plug and the plug84 and stem 88 being carried by the plug 75. By removing the plug 75 theentire check valve can be readily cleaned as desired. Additionall I haveprovided a simple means by whic the accumulation of oil and water in thecheck valve can be drawn off. It is necessary to insure that no oilladenair enters the air reservoir. Oil-laden air will do great injury toautomobile tires. By the use of my retort or chamber B, to-

gether with my check valve, this happening 7 is doubly guarded against.

In Fig. 8 of the drawings, a modified form of my check valve is shown.Reference numerals similar to those in Fig. 7 are used upon Fig. 8. Iwish it to be understood that it is not necessary that the pressuregauge be mounted in the check valve. In the modi-v fied form of thecheck valve the plunger chamber 69 is closed by a cap 90, in place ofthe cap 70 of the preferred form. In the modified form, I have done awaywith the plug 84 and its hollow stem 85, using in their place theordinary pet-cock 91 for draining the lower plug chamber 80. The checkvalve construction shown in the modified form would be put to manyu'sesas will be readily understood, so likewise can the preferred formof the valve.

From the foregoing description it will be seen that in all the forms ofthe check valve that the screen at the bottom of the valve collects allforeign matter carried by the air passing through the, valve. Thisforeign matter may possibly be water, oil, dirt or flakes of carbon dueto carbonization in the pump and prevents any of this foreign matterlodging on the seat of the check valve which would cause the check toleak and thereby impair the operation of the whole system.

Having thus described my invention what I claim and desire to secure byLetters Patent is:

1. A compressor mechanism, comprising a compressor having low and highpressure cylinders, an intercooler connecting said cylinders, a flywheel having fan, blades, a housing between said fly wheel and saidcylinders, and the intercooler mounted in said housing, for the purposedescribed.

2. In a compressor mechanism, a compressor having a plurality ofcylinders, a fly wheel having fan blades, a housing between the flywheel and the cylinders, an intercooler mounted within said housing andconnecting the compressor cylinders, and the housing adapted to directthe flow of cooling air from the fly wheel around the intercooler overthe compressor cylinder wall, for the purpose described.

3. In a compressor, the combination of low and high ressure cylinders,fan blades for creating a ow of air towards said cylinders, anintercooler connecting said cylinders and comprising a coiled pipearrangement between the cylinder and said fan blades, and means fordirecting the flow of air from the fan blades over the intercooler. 4. Acompressor mechanism, comprising a compressor having low and highpressure cylinders, an intercooler in the form of a coiled pipeconnecting the said cylinders, a fly-wheel havin fan blades a housingbetween the said y wheel and said cylinders, and the intercooler mountedin said housing, for the purpose described.

5 air compressor and liquid separat-' mg mechanism, comprising aplurality of cy inders in parallel relation mounted above a compressionreceiving'chamber, an intercooler comprising a coiled pipe connectingsaid cylinders and being positioned between the cylinders and thecompressor fly-wheel, fan-blades on said fly-wheel for causing a flow ofair, and a housing for directing said air-current againstsaidintercooler, compres sor cylinders and compression chamber.

6. n a compressor mechanism, a compressor having low and high pressurecylinders,

the cylinders provided with radiation accelerating means, an intercoolerconnecting the cylinders, '21 fly wheel provided with fan blades, ahousing between the fly wheel. and the cylinders, the intercoolermounted in said housing, and the hous'in adapted to direct wheel, thecom ressor mounted upon the air receiving cham 1', and means forconfining and directing the course of air current created by the flywheel blades.

8. A compressor mechanism constructed as defined in claim 7, the meansfor confining and directing the air current of the fly wheel bladescomprising a housing mounted between the fly Wheel and the enginecylinders.

9. In a compressor mechanism, a pair of vertically arranged parallelcylinders, one of said cylinders being a high pressure cylinder and theother a low pressure cylinder, an intercooler connecting the cylinders,a fly wheel for the compressor provided with fan blades, the intercoolersupported between the cylinders and the fly. wheel, means to direct theair blast from said fan blades over said intercooler, an air receivingand liquid separating chamber in communication with the high ressurecylinder, and the air receiving cham r in communication with an airreceiving reservoir.

10. A two-stage compressor with' intercooler com rising a re atively lowand a relatively hlgh ressure cylinder,thelow pressure cylinder beinglarger in diameter, a crank shaft operatively connected with pistonslocated in the r tive cylinders, a. fan at .tached to the driving shaftand located ad 'acent one of the said cylinders, an intercooler liavinits ends'connected respectively with the sald cylinders, theintermediate portio of the intercooler having a vertically arranged coillocated between the fan and adjaoent one of the said cylinders, andmeans for confining the air current from said fan whereby air is forcedthrou h the coil for cooling the compressed air fed to the highcompression cylinder.

11. A two-stage compressor with intercooler comprising relatively lowand relatively high pressure cylinders, a crank shaft operativelyconnected with pistons located in the said cylinders, a fan locatedadjacent one of the said cylinders, and an intercooler having its endsconnected respectively with the said cylinders and its intermediateportion formed in a vertically arranged convolutc coil, and asurrounding housing arranged be tween the fan and the said cylinderwhereby all of the air is forced through the said coil for the purposedescribed.

12. A two-stage compressor and intercooler comprising relatively low andhigh pressure cylinders, a drive shaft operatively connected withpistonslocated in said cylin mediate portion arranged in a vertical planebetween the said fan spokes and one of the said-cylinders, and the lowerportion of the coil extending below the housing, whereby air is forcedthrough the lowerportion of the coil and through the upper portion andagainst the said cylinders for thepurpo'se' specified. I p

13. A two-stage compressor and intercooler compressor comprisingrelatively low and high pressure cylinders, a crank shaft Op- 3.eratively connected With pistons located in' the said cylinders, a flywheel having its spokes formed into fan blades, the high pressurecylinder located adjacent the said fly wheel and an intercoolerconsisting ofa pipe having its ends connected respectively with thetwo-stage cylinders and arranged. in a vertical convolute coil, and ahousing for con- 'fining the air set in motion by the fan, and

directing the same over and through the inter-' cooler, whereby air isreceived directly from the low pressure cylinder and cooled in the coiland air is also forced directly on the high pressure cylinder which ishotter than the low pressure cylinder, therebycooling the air in theintercooler and coolingbothof the cylinders to substantially a properWorking temperature.

14. A two-stage compressor and intercooler comprising a drive shaft,relatively high and low pressure cylinders arranged tandem-in. a

line with the drive shaft, the drive shaft op,-

eratively connected with pistons located in the said cylinders, afanattached to the drive shaft, the high pressure cylinder located adjacentthe said fan, and an intercooler pipe having its ends connectedwith thesaid cyl-in- .ders and having an intermediately arranged vertical coillocated between the said high pressure cylinder and the said fan, ahousing between said fan and said high pressure cylinder, theintercooler positioned in said housing whereby part of the air strikesthe said high pressure cylinder before striking the low pressurecylinder, thereby maintaining the two cylinders 'at substantially thesametemperature'. I l' In testimony whereof I hereunto afiixmysignature.

GEORGE EDGAR HAZARD.

